Peugeot 308cc RHF Engine Will not start

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Iver
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Peugeot 308cc RHF Engine Will not start

Post by Iver » Thu Jun 06, 2019 6:46 pm

PSA RHF 308 Inj plus Starter.psdata
(1.53 MiB) Downloaded 44 times
PSA RHF 308 Inj cam crank frp.psdata
(2.47 MiB) Downloaded 55 times
Hi Guys

In need of some help with this car. It will crank but wont fire or even try to although I can get it to run on brake cleaner quite well, take the brake cleaner away and it stops.

There are no fault codes stored in any Modules, occasionally on extended cranking I get P0215 Main Relay Short to Ground. I have checked that relay and wiring both with a scope & a bulb and there is no issues, we can be cranking for a good while and will not always get that code. Autologic,

Going through the data streams we have Cam/Crank Synchronisation, the vehicle is not immobilised, all temperature & pressure values are plausible.... it all looks good to us and we have made comparisons to a similar vehicle. Of course we cautious and understand that similar is not same.

With the lack of any direction from a DTC or Datastream we could only guess from the Brake Cleaner test that we may have a fuelling issue.

I have scoped Injector 1 current, Starter Current (for TDC Reference), Cam, Crank & Fuel Rail Pressure and attach the waveforms.

Any pointers and testing ideas would be much appreciated by ourselves and our customer.

Thank You.

landroverman1958
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Re: Peugeot 308cc RHF Engine Will not start

Post by landroverman1958 » Fri Jun 07, 2019 6:06 am

Good morning,why dont you check your pids for fuel pressure,desired v actual?check your rail pressure sensor circuit plausibilty by unplugging sensor,and looking at open circuit code,plausibility voltage for rail sensor .5volt koeo 5v unplugged.
The injectors will not fire unless over 220bar in rail supplied by high pressure pump,check priming,supply fuel condition.

Iver
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Re: Peugeot 308cc RHF Engine Will not start

Post by Iver » Fri Jun 07, 2019 7:42 am

Landroverman

Thank you for the reply.

"Actual" Fuel pressure I can confirm matches and exceeds "Desired". You can see from the Waveform that the FRP is plausible and acceptable.

When i have "helped it with brake cleaner I have fuel pressure up at 1000 bar and Engine Speed up to 1200 rpm. Right or Wrong I have at this stage ruled those out as culprits.

Looking at the Injector Current & Starter Current (which I have used for TDC reference) I can clearly see why it wont start. The Injectors appear to be fired but never at or near TDC. That shows me that meaningful combustion will not take place, however I cannot establish why.
Attachments
308 cc.jpg

KimAndersen
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Re: Peugeot 308cc RHF Engine Will not start

Post by KimAndersen » Sat Jun 08, 2019 9:54 am

Hello

When I look at the rail pressure sensor voltage and compare this with the time before the engine starts to rotate - is there something odd going on in the pressure rail. There shouldn't be any pressure in the rail at that stage - you have a voltage reading from the FRP sensor at 1.7 volt which equels a pressure at 500 bar !!!.

Try to make a new capture of FRP sensor with the key on engine off (KOEO) and look for a voltage at 0.5 volt which equels 0 Bar pressure as Landroverman pointed out - the basic stuff first before doing anything else.

How did you measure the FRP sensor - at the sensor itself !.

RAIL_PRESSURE_VS_CAMSHAFT_ROTATION.jpg

Regards
Kim

Iver
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Re: Peugeot 308cc RHF Engine Will not start

Post by Iver » Sun Jun 09, 2019 11:35 am

Hi Guys, and thanks for the great replies.
why don't you check your pids for fuel pressure,desired v actual?check your rail pressure sensor circuit plausibility by unplugging sensor,and looking at open circuit code
Having read both replies now I am not quite sure about rail pressure, it was 2 weeks ago that I looked at it last, I did look at rail pressure and it was well above 220 bar which I then dismissed as the culprit.

Most of my attention went towards the Injectors constantly firing, One trace shows 12 Amps & the 16 Amps being drawn by Injector 1 so I deemed that was not noise or a measurement error.
is there something odd going on in the pressure rail. There shouldn't be any pressure in the rail at that stage - you have a voltage reading from the FRP sensor at 1.7 volt which equels a pressure at 500 bar !!!.

How did you measure the FRP sensor - at the sensor itself !.
Indeed I can see the FRP voltage at 1.7v rising to a peak of 2,4v then settling at 2.1v. Now that Kim has drawn my attention to this I am thinking all these figures are too high. Perhaps 0.5v rising to around somewhere in the region of 0.8 - 1.2v at cranking might be better.

All the measurements were taken back probed at ECU.

I will be looking at this car tomorrow, armed with this info I hope to have a better chance with it.

I have another question, why are those injectors being fired in that way ?? My guess, and it is only a guess, is that FRP is excessively high, and the control strategy is to fire the injectors to lower Rail pressure and concurrently not fire near TDC so the Engine is not able to start ??

In hindsight I have read about FRP being too high to allow starting but never experienced it myself.

Thanks for the input guys & I will post some more measurements & conclusions once I have them.

Iver
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Re: Peugeot 308cc RHF Engine Will not start

Post by Iver » Mon Jun 10, 2019 12:13 pm

Not so sure now what I was measuring or how those voltages occurred. It was a few weeks ago that I looked at the car.

I have learnt today from the Garage that A Genuine New BSI has been fitted & coded. Another Engine ECU has been Matched & Fitted. The Old EcU is now back on the car. This parts were exchanged on the advice of Autologic Helpline.

I took a reading of FRP with KTS this morning and found
308 cc FRP.PNG
I'm quite happy with those readings (please correct me and if I am wrong) needless to say the engine will not start or try to. However, as always any advice on moving forwards will be appreciated.

I can also confirm that FRP doe drop off to 1 Bar 20 seconds after cranking stops.
RHF FRP 1.PNG
Many thanks for looking

KimAndersen
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Re: Peugeot 308cc RHF Engine Will not start

Post by KimAndersen » Mon Jun 10, 2019 6:56 pm

Hi Iver

I did a little research in my arkive of delphi documents related to common rail system where there are a description of your DTC P0215 that you sometimes get during long cranking time.

This DTC P0215 is the supply power to the ECU and despite your great effort to check this relay - would I take a closer look at this relay and the power supply to the ECU once more - just to be 100 % sure.

You could make a byepass wire to the ECU - just to verify !!!. I dont have a wiring diagram, so I cant help you there.

I know, its not much of a help. :wink:

Regards
Kim

Iver
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Re: Peugeot 308cc RHF Engine Will not start

Post by Iver » Mon Jun 10, 2019 8:45 pm

This DTC P0215 is the supply power to the ECU and despite your great effort to check this relay - would I take a closer look at this relay and the power supply to the ECU once more - just to be 100 % sure.

You could make a bypass wire to the ECU - just to verify !!!. I dont have a wiring diagram, so I cant help you there.
Hi Kim.
I do have the correct description for P0215. I do have a wiring diagram for and have checked and double checked that relay and ECU power supplies & earths with a scope & a bulb, I did use a bypass wire too. We also swapped the relay.

To me Injector 1 Firing continuously some 120 times in 720 degrees is a worry.
308cc 2.jpg
And please note that at TDC it stops firing, What are your thoughts on that ?

thank you.

landroverman1958
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Re: Peugeot 308cc RHF Engine Will not start

Post by landroverman1958 » Tue Jun 11, 2019 6:18 am

Good morning,I would carry out a back leakage test of the injectors,to make sure there is not any excessive leaks,you could disconnect the injectors electrically unplug and the metering valve-imv crank the engine and see how fast the pressure rises in the rail,and if the pressure holds as the pressure cannot be released by the ecu,
The pressure should build very quickly,under a second and build up to 1500 to 1800bar and hold.if it does not there is a leak in the high pressure side or there is bad supply flow through the filter.

Iver
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Re: Peugeot 308cc RHF Engine Will not start

Post by Iver » Wed Jun 19, 2019 3:22 pm

Landroverman.

I have not looked at this car recently but can confirm that we did a Leak off test. Rather unconventional but we did not attach pipes or bottles, however on a good 30 seconds of cranking no fuel was seen from any injectors. Fuel Pressure did exist in the rail at time of test.

I agree with you and take your point that the the Low Pressure supply to the pump must be good for the High Pressure side to produce good pressure. We are aware that the SCV or IMV can be manipulated fully open and the Pressure regulator fully closed to gain maximum pressure build. We have the Delphi High pressure kit and also some home made Blanks that we can use on the fuel pump,fuel rail & high pressure pipes to isolate where the loss of pressure maybe.

I may not be looking at that car this week but will be happy to test the high and low pressure sides when I do.

My testing so far has shown that I have good Rail Pressure but (in my Opinion) that Injector is firing too many times and at the wrong times. Could that be a symptom of poor fuel pressure even though the ECU "thinks" Rail pressure is matching the desired value ??

That is the strangest Injector Firing waveform I have seen since I have been Scoping them (near 20 years)

Am I missing something here ?
thank you.

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